Asier Goiria's second-half winner handed 10-man Numancia a vital win in their battle against relegation from the Primera Liga.
Almeria - whose coach Gonzalo Arconada was handed a vote of confidence this week after five defeats in seven matches - took an undeserved lead through Esteban Solari's controversial penalty.
But Numancia hit back before the break through Javier Del Pino and they held on following Goiria's goal despite the dismissal of Jose Barkero for two bookings.
The home side made a blistering start in pursuit of a crucial three points and were twice within a whisker of claiming the lead in the opening seven minutes, but were denied by the woodwork on both occasions.
In the sixth minute, Barkero played a free-kick into the Almeria box which Gonzalez Sergio Ortega turned onto the post from six yards.
Then, just 70 seconds later, defender Manuel Pavon struck the upright with a shot from 12 yards to leave coach Sergio Kresic cursing his luck.
The Croatian's mood was hardly improved when, after 10 minutes, the visitors defied the run of play to win a penalty.
Domingo Cisma was deemed to have fouled Gutierrez Robles Juanito at a corner and, after a prolonged spell of protest from the home side which brought two bookings, Argentinian Solari stroked the resulting spot-kick into the bottom corner in the 12th minute.
After 20 minutes Numancia claimed the equaliser that their early performance deserved.
With the frustrated home side threatening to lose their cool after the controversial penalty decision, Del Pino drilled home from 12 yards after Juan Quero's cross to make it 1-1.
Barkero then rifled a free-kick wide but the match finally began to settle after a breathless opening quarter which brought five bookings from referee Cesar Muniz Fernandez.
The influential Juan Quero also twice shot off target for the Rojillos as the break approached, while Mosquera Julio Alvarez's effort over the bar for Almeria was the last meaningful action of the first period.
If Goiria harbored any lingering resentment over the nature of the penalty awarded against his team, it took just seven minutes of the second half for him to make his point as he put Numancia into the lead for the first time.
Collecting Barkero's header on, the striker shot into the bottom corner from close to the penalty spot.
The match was thrown back into the balance with 21 minutes left, though, as Barkero was sent off for a second yellow card after a foul on Palazon Juanma Ortiz.
Almeria's Brazilian Santos Guilherme tried his luck from the edge of the box soon afterwards but his effort was off target, while Miguel Angel Corona also failed to trouble Colinas Juan Pablo in the Numancia goal from similar range.
And despite late pressure from the visitors, Kresic's men held on for a win which takes them to within a point of their opponents and pushes Arconada to the brink.
